Platform invoke relies on metadata to locate exported functions and marshal their arguments at run time. The following illustration shows this process.
A platform invoke call to an unmanaged DLL function
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When platform invoke calls an unmanaged function, it performs the following sequence of actions:
Locates the DLL containing the function.
Loads the DLL into memory.
Locates the address of the function in memory and pushes its arguments onto the stack, marshaling data as required.
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Locating and loading the DLL, and locating the address of the function in memory occur only on the first call to the function. |
Transfers control to the unmanaged function.
Platform invoke throws exceptions generated by the unmanaged function to the managed caller.
See Also